In recent, secondary batteries have been used as power sources in mobile information terminals such as portable phones, notebook computers, personal digital assistants (PDA), and the like, electric vehicles, backup power, and the like. According to the related art, secondary batteries configured of the electrode assemblies having a structure according to the related art and formed by stacking electrodes having the same area and shape on one another have mainly been provided.
In the case of such an electrode assembly according to the related art, as disclosed in Japanese Patent Laid-Open Publication No. 2008-091099, it was attempted to maintain a form of an electrode assembly in which electrodes are stacked and a shape of the electrode assembly by taping a side of the electrode assembly. As illustrated in FIG. 1, according to the related art, in order to maintain a shape of the electrode assembly according to the related art and a stacking form of the electrode, tape was attached to sides of the electrode assembly.
However, in accordance with the miniaturization, integration, and the like of recent electronic devices, various battery designs have been in demand. Therefore, while demand for batteries having irregular structures such as batteries having a step, and the like, has increased, the use of standard batteries such as batteries according to the related art has gradually decreased.
However, in the case of irregular structural batteries having a step, since at least one of a size and a shape of electrodes used for the formation of an electrode assembly is different, it may be difficult to maintain a shape of an irregularly structured battery and a stacking form of electrodes.